TiVoTempSensor

(Originally posted on TiVo Community Forum 17-Nov-2002)

DTiVo's DO NOT RUN HOT!!! (Really)

(Somebody may have already done this and reported it, but I've never seen any references to it. So if this has been done before, I apologize for wasting space in this forum.)

Ya know everybody says DTiVo's run warm. Me included. I've even resigned myself to the fact DTiVo's run warm. I installed an additional fan in one. I raised up another. I tried the rolled up paper. I've tried just about every suggestion anyone has made. I've used 5400RPM drives, I've replaced 7200RPM drives with 5400RPM drives. All these things maybe would make a degree or two difference, but they weren't cumulative. And I've come to a conclusion: DTiVo's run warm. Short of opening them up and keeping the cover off, DTiVo's are going to run warm.

BUT, I got to thinking last night. Of all the talk of DTiVo's running warm, and that depends on where its temperature sensor is, and where the DTiVo's installed, and what drives are in it, and what the phase of the moon is, and yada yada yada. I never heard of anyone taking a scientific look at this. So I did. Or at least attempted to. Don't go looking for any margin of error in my analysis, and I will ignore any posts telling me my analysis was flawed or not scientific, but....

Seeing I have a couple of two three (that's Wisconsin speak for more than one) Radio Shack digital temperature thingamabobs laying around that have outdoor temperature probes, I decide to stick one in one of my DTiVo's. I chose the DTiVo that's sitting on top of my Entertainment Center (cuz it was easy to get at, go figure, and already had the screws for the cover out) and stuck the temperature probe in it and closed it back up and let it normalize for over 12 hours. Guess what? DTiVo's DON'T RUN WARM.

I placed the sensor hanging open air, between the two disk drives pointed towards the rear of the case. When the DTiVo was telling me the temperature was 48C (Normal), my Radio Shack sensor told me it was 85.5F (30.2C). I then looked at the maximum temperature it had attained and that was 87.8F (31.0C). I then thought, ok that's there (i.e. that position in the case) but that might not be representative. So I thought of moving it around in the case, under the drives, by the divider, etc.(and I still might do that), but let's go for worst case, where would it likely be the warmest? (From a motherboard standpoint.) My answer was, where the fan exhausts! So I moved the sensor there, closed it up, and let it normalize again for a few hours. Well, once again the DTiVo was telling me the internal temperature was 48C (Normal) while the fans exhaust air temperature hovered around 103.1F (39.5C), and the highest it reached was 104.5F (40.2C).

So, in conclusion (my conclusion), if the temperature that is being reported by the DTiVo is in fact the PPC die temperature, or even if it is anywhere near it, or even if it's not even close to it, we have nothing to worry about. Let's say it is the PPC temp, and the internal case temp is 30.2C as I have determined, that's way better then any of my PC's. And my PC's aren't no slouches. The least number of cooling fans any of them have (excluding CPU fans, video board fans, etc.) is 3, and the average is 4. As an example the three that are the easiest for me to do a quick check on have the following temperatures (CPU/case) 54C/46C, 52C/38C, and 51C/34C. So 48C/30C?? I'm not even going to give it a second thought any more, or even consider installing an additional fan, or cutting more holes in the case, or jacking it up with 3' 7-1/2" stilts, or yada yada yada. In my opinion, the temperature the DTiVo is displaying is the PPC temp, or very, very close to it, and that running at ~50C, is not problem.

This also sheds some light on the fact that the Maxtor drives are not running at only 5C below their rated maximum, more like 25C. Worst case 15C.

Basically we're all a bunch of worrying Nellie's worrying about this and trying to decide 5400 verses 7200 and which of the latest Model 4000 Rev B Tornado Cyclone SuperWhirl(tm) fans to install, and should I install 4 or 6 of them, when in fact, the DTiVo Engineers knew exactly what they were doing.

Gawd, I'll finally be able to sleep tonight....

P.S. Oh and, the ambient room temperature according the same Radio Shack temperature gizmo (it's a dual display unit at that) was 73.9F (23.2C).

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